In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome.

True

Explanation:

This given statement is true.

A dominant allele is the one which overrides the expression of the other allele of the same gene.

For instance,

R is a dominant allele and give red color to flowers while r is the recessive allele and give white color to  the flowers

Rr together will give red color to flower because R will dominate r